﻿




using System;
using System.Net;
using System.Web;

namespace Hotpot.Extensions
{
    public static class IPAddressExtensions
    {
        public static long ToLong(this IPAddress address)
        {
            if (address.AddressFamily != System.Net.Sockets.AddressFamily.InterNetwork)
            {
                return 0;
            }

            switch (address.GetAddressBytes().Length)
            {
                case 4:
                    return BitConverter.ToUInt32(address.GetAddressBytes(), 0);
                case 8:
                    return (long)BitConverter.ToUInt64(address.GetAddressBytes(), 0);
                default:
                    throw new Exception("Invalid IPv4 Address passed, length not 4 or 8 bytes");
            }
        }

        /// <summary> 
        /// 取得客户端真实IP。如果有代理则取第一个非内网地址 
        /// </summary> 
        public static string ClientIPAddress
        {
            get
            {
                string result = String.Empty;

                if (HttpContext.Current == null)
                {
                    //如果是CS客户端
                    IPHostEntry ips = Dns.GetHostEntry(Dns.GetHostName());
                    for (int i = 0; i < ips.AddressList.Length; i++)
                    {
                        if (i == 0)
                            result += ips.AddressList[i].ToString();
                        else
                            result += (";" + ips.AddressList[i].ToString());
                    }
                    return result;
                }

                result = HttpContext.Current.Request.ServerVariables["HTTP_X_FORWARDED_FOR"];
                if (!string.IsNullOrEmpty(result))
                {
                    //可能有代理 
                    if (result.IndexOf(".") == -1)     //没有“.”肯定是非IPv4格式 
                        result = null;
                    else
                    {
                        if (result.IndexOf(",") != -1)
                        {
                            //有“,”，估计多个代理。取第一个不是内网的IP。 
                            result = result.Replace(" ", "").Replace("'", "");
                            string[] temparyip = result.Split(",;".ToCharArray());
                            for (int i = 0; i < temparyip.Length; i++)
                            {
                                if (temparyip[i].IsIPAddress()
                                    && temparyip[i].Substring(0, 3) != "10."
                                    && temparyip[i].Substring(0, 7) != "192.168"
                                    && temparyip[i].Substring(0, 7) != "172.16.")
                                {
                                    return temparyip[i];     //找到不是内网的地址 
                                }
                            }
                        }
                        else if (result.IsIPAddress()) //代理即是IP格式 
                            return result;
                        else
                            result = null;     //代理中的内容 非IP，取IP 
                    }

                }

                //string IpAddress = (!string.IsNullOrEmpty(HttpContext.Current.Request.ServerVariables["HTTP_X_FORWARDED_FOR"])) ? HttpContext.Current.Request.ServerVariables["HTTP_X_FORWARDED_FOR"] : HttpContext.Current.Request.ServerVariables["REMOTE_ADDR"];



                if (string.IsNullOrEmpty(result))
                    result = HttpContext.Current.Request.ServerVariables["REMOTE_ADDR"];

                if (string.IsNullOrEmpty(result))
                    result = HttpContext.Current.Request.UserHostAddress;

                return result;
            }
        }
    }
}